Generally, centrifuges are apparatuses m which a rotor containing samples is rotated at high speed to apply a high centrifugal force to the samples, so that a high density fraction is moved radially outwards and a low density fraction is moved radially inwards, thus separating the fractions from each other.
FIG. 1 is a sectional view showing a conventional automatic balancing rotor for centrifuges. As shown in FIG. 1, the conventional automatic balancing rotor for centrifuges uses a mechanism, in which a lever central body 636 is horizontally moved according to a control algorithm, to compensate for imbalance between samples contained in buckets supported by rotational aims 632. Here, the lever moving mechanism includes a worm 662 which is axially coupled to a lever moving motor 652, a worm gear (not shown) which engages with the worm 662, a pinion 666 which is coaxially coupled to the worm gear, and the lever central body 636 having a rack 636a, which engages with the pinion 666.
Furthermore, a pressure sensor 690 is provided under each rotational arm 632 to measure the weight of the sample contained in the associated bucket (not shown). A wiring layer 562 is integrally coupled to a lower part of the rotor to receive an electrical signal from the pressure sensors 690 and transmit an electrical signal to the lever moving motor 652 according to a control algorithm, thus balancing the centrifuge.
The conventional automatic balancing rotor for centrifuges having the above-mentioned construction senses imbalance of the samples by measuring the weight of the buckets provided at both ends of the rotor lever, and controls the distance between each bucket and a rotating shaft of the rotor according to the weight difference of the samples, thus applying the same centrifugal force to the opposite buckets containing the samples. Thereby, the samples contained in the buckets maintain a dynamic balance state during the rotation of the rotor for centrifugal separation. More details are described in Korean Application No. 10-2002-0017498 (publication date: Apr. 17, 2002) which was filed by the inventor of the present invention, therefore further explanation is deemed unnecessary.